Upgrade or Sell?

Hi everyone,

I took an 8 year break from airsoft, but this weekend I went for a game and I'm finally back in.

I still have my G&G TR15 Raider XL, and it ran fine this weekend. But it's running quite low on FPS (around 200ish), so my plan was to give it a good service and pop a new spring in. Then eventually maybe a rewire so I can run lipo etc.

But my question is, how much have guns improved in the last 10 years? Would I be better off selling and buying something newer instead of pumping more money into the TR15? Or just upgrade what I have?